All is not lost - there is reaction against this by some parents who want him rehired.
See:
July 21, 2005, 10:06AM
Fired crossing guard gets show of support
Parents want HISD to rehire 79-year-old who was terminated for refusing drug test
By JASON SPENCER
Copyright 2005 Houston Chronicle
http://www.chron.com/cs/CDA/ssistory.mpl/metropolitan/3275476
"It would completely destroy our ability to keep children safe if we allowed people to refuse the drug or alcohol test," he said.
Bureaucratic group think always trumps good sense.
I'd say common sense, but if common sense was truly common, they'd have some of it.
Where's the ACLU when you need them???